Note: Add smoked fish trimmings to fish stock or water and add, if desired, some carrot peelings onion and celery scraps and fresh thyme, simmer 1 hour then use this in the soup where required.
In a large soup pot, heat olive oil over medium heat, add sausage casings and cook for 10 minutes, stirring to break up pieces into small bits. When mostly cooked but not crispy, add carrot, onion and celery and continue cooking another 10 minutes. Add remaining ingredients, except fish, and bring to a simmer, stirring bottom of pan to keep from sticking. When simmer has been reached, cook 10 minutes, or until potatoes are mostly cooked. Add fish and simmer gently until fish flakes, about 10 minutes. Adjust seasoning and top with chopped parsley.
Tip: Best enjoyed the next day when reheated so that flavours are infused.